Throttle Body question...

[JOHNNYCASH]

What needs to be done to switch my 1990 Throttle body to a 1991-1994 or is this even possible?

Paul

[dsm_gsx97]

Not sure if it is possible, but even if it were you can pick up a '91-94 TB for $25 which is way cheaper than trying to fix that thing.

[Mirage]

You will need to make adapter harnesses for both the TPS and idle switch. not a big deal.

I *believe* that the ISC uses the same plug throughout the years, so you can simply bolt your '90 ISC onto the '91+ TB.

Marcus

[RBWTrans]

You will need to make adapter harnesses for both the TPS and idle switch. not a big deal.

I *believe* that the ISC uses the same plug throughout the years, so you can simply bolt your '90 ISC onto the '91+ TB.

Marcus

The plug's the same but shorter. You'll still need to make an extension for it.

[Mirage]

The plug's the same but shorter. You'll still need to make an extension for it.

Wrong.

The TPS on a '90 has a 2x2 plug which also houses the idle switch wire (3 wires for TPS, 1 wire for Idle Switch).

Wheras the '91+ has a 4x1 plug while it only uses 3 wires in it. The idle switch has it's own wire coming off of the harness.

Now. The ISC has the same plug, but he can simply use his '90 ISC which has the pigtail on the newer TB.

Marcus

[RBWTrans]

Thank you. I was talking about the ISC. I wasn't saying the TPS or IS would hook right up. I didn't however, think about swapping the 90 ISC into the newer throttle body. They look so different that I never even considered it.

[JOHNNYCASH]

Well its possible to switch the ISC, i did it and rewired it also. The only problem was after I switched everything over, the 1991-1994 TPS was different and interfered with my fuel rail and lines; now if i switched to AN fittings it would have worked. As of now I am just going to keep my old TB on and when I come accross another one I will swap it out.

Paul

[RBWTrans]

Just another thought for you. I've been rebuilding my throttle bodies using a/c o-rings behind the old throttle shaft seals. I knock out the old seals and burn them with lighter fluid to remove all of the old rubber. I coat the orings with a generous amount of di-electric grease and then tap the old seal shells on top of them to hold them in place. I also took an old 14mm socket and ground off the outer ring into 4 points for adjusting the water temp idle air bypass. It's not that hard, but definately worth the effort. I didn't think about the fuel rail and inlet line. I ran into that a few months ago trying to use a 90 fuel rail on my 93. The good news is that the rail is the same on the more common n/a engines as well. Good luck with your quest for a boost leak free ride.